If the sun would be at the back of some walker, then the
shadow of his head is somewhat in advance of his feet. That is, here the ardor
for the slaying is such that like my shadow, my head is two steps in advance
of my feet; as he has said previously, that 'door and walls have devoted themselves
to their shadow' [an inaccurate reference to {58,7}?].
(197)

He says, we go running after the Executioner toward the
execution-place with such happiness that as our feet are advancing very quickly
in the ardor for execution, the shadow of our head is going two paces ahead
even of them. If the sun is situated toward the back, then the shadow advances
ahead. (255)

We feel such happiness at being slain without any crime,
by the order of the beloved or of some tyrant, that we are going ahead of
the Executioner in the way that the shadow of our head goes two paces ahead
of the shadow of our feet. (346)

FWP:

This verse is a kind of study in the versatile little postposition se . It occurs three times in the two lines, and each time in a different sense. The use in the first line is instrumental: 'with' an extraordinary joy; since Urdu is remarkably adverb-poor, such postpositional phrases with se are very common where English would have adverbs.

Then in the second line two such phrases appear in close succession. The earlier case, apne saa))e se , looks like a good candidate for 'by means of' our own shadow, which is also a standard use of the postposition. Only after reading the rest of the line do we go back and realize that in this context it could also be short for jaise , 'like, in the style of' our own shadow. By contrast, the later case is straightforward: paa;Nv se , 'from the foot', another standard use of the postposition.

Thus we walk
ahead of the Executioner because of our eagerness to experience death. The analogy in the second line is the way when someone walks with the sun behind him, his shadow falls ahead of him, so that the head of his shadow is farther away than (and thus ahead of) the foot of his shadow.

The multivalence of kih , which can mean either 'so that' or 'since', permits the causal relationship to run either way. Does our joy cause our shadow to mirror this eagerness, or does our shadow's movement inspire or embody our joy?

Also, of course, the idea that the head is somewhat separated
from the feet is all too appropriate to a situation in which the speaker is
about to be decapitated. And there's the related wordplay of 'head' and 'foot' and 'footstep'. Vivek Gupta points out (Feb. 2012) that in Arabic nashaa:t means 'activity', so that for Arabic-knowers there might be an extra layer of wordplay (for indeed our 'activity' is strange).

Arshi suggests a comparison to {45,4},
which is thematically apt. But I suggest looking at {208},
with its refrain of mire aage , to see all the clever
ways Ghalib uses aage when he's in the mood.